1) Heat the oil in a large saucepan and then add the onions. Cook on a medium heat until soft. 2) Add the celery, leek and potato. Cover with a lid and allow to sweat for 5 minutes. 3) Remove the lid. Pour in the stock and add the carrots and any chunky bits of broccoli stalk. 4) Cook for 10 – 15 minutes until all the vegetables are soft. 5) Add the rest of the broccoli and the spinach and cook for a further 5 - 7 minutes. 6) Transfer to a blender and blitz until smooth. 7) Stir in the cheddar and allow to melt. Re heat if needed.